เปรียบเทียบวิธี

	ผลกระทบจากเพดานและพื้น	การสร้างมาตรวัดแบบลิเคิร์ท
สาขาวิชา	การวัดทางจิตวิทยา	การวัดทางจิตวิทยา
ตระกูล	Process / pipeline	Process / pipeline
ปีกำเนิด	2000	1932
ผู้ริเริ่ม	Classical psychometrics	Rensis Likert
ประเภท	Measurement validity assessment	Summated rating scale methodology
แหล่งต้นตำรับ	McHorney, C. A. (2000). Ten recommendations for measuring health status. Health-Related Quality of Life Outcomes, 2(1), 1-5.	Likert, R. (1932). A technique for the measurement of attitudes. Archives of Psychology, 22(140), 1-55.
ชื่อเรียกอื่น	Floor effect, Ceiling effect, Psychometric floor effect, Measurement floor	Likert summated rating scale, Summated rating scale construction
ที่เกี่ยวข้อง	4	5
สรุป	Floor and ceiling effects are psychometric phenomena in which a disproportionately large proportion of respondents achieve the lowest (floor) or highest (ceiling) possible score on a measurement scale. These effects compromise scale reliability and responsiveness, limiting the instrument's ability to distinguish among respondents and detect meaningful change over time. Systematic assessment of floor and ceiling effects is essential for evaluating the psychometric adequacy of health-related quality-of-life scales, functional status measures, and other patient-reported outcomes.	Likert scale construction is a systematic methodology for developing attitude measurement instruments using summated rating scales. Introduced by Rensis Likert in 1932, it enables researchers to quantify latent constructs such as attitudes, beliefs, and psychological states by aggregating responses across multiple items. The method remains foundational to quantitative social and health sciences research.